Another piece of advice.... relax. Your body is capable of doing more than you realize sometimes, but if you let fear and other things your mind can toss your way get in control, you can sometimes fall short of what you're actually capable of.
Given the bike you have, focus on spinning and not grinding your way up the hill. I have a hill near me that I started riding when all I had was a hybrid and it's that grade at its worst, although it doesn't stay there long and averages about 3-4 percent. I have "fonder" memories of climbing that hill on a hybrid than I do on either of the 2 road bikes I've acquired since then.